1 . Field of the Invention
This invention relates to a discharge apparatus and method used for diesinking and other metal machining applications, and more particularly to a laser guided discharge apparatus and method used for machining the surface of a workpiece.
2. Description of the Prior Art
Discharge machining is used to cut and shape metal products. In conventional discharge machining, the workpiece is disposed opposite the work electrode and a discharge is induced from the electrode to the workpiece, with the workpiece being machined by the impact of the discharge. There is a diesinking discharge machining method and a wire discharge machining method. In the former method, the machining is carried out with an electrode having the required shape to which the workpiece is to be machined pressed onto the workpiece, while in the latter method cutting is performed using a straight electrode.
The conventional discharge machining methods therefore use a technique in which the workpiece and electrode are positioned in opposition to each other and a discharge is produced from the electrode to the workpiece, whereby the heat of the discharge melts a portion of the workpiece, and the explosive vaporization of the machining fluid that takes place at the same time is used to blow away the melted portion. Thus, in both of the above discharge machining methods the discharge electrode has to be arranged opposite the part of the workpiece to be machined. Even in the case of conventional laser-induced discharge machining, the discharge electrode has to be more or less directly opposite to the portion to be machined. As such, a discharge machining apparatus has only been able to be used to machine parts which can be directly seen from the discharge electrode, meaning that machining the inside of a pot with a small mouth, for example, has not been possible with such an apparatus. This has made it desirable to develop discharge machining technology that can be used to machine parts which are not in a direct line of sight position relative to the electrode.
An object of the present invention is to provide a discharge machining apparatus and method that can be used to machine the rear surface of a workpiece or other such parts that are not in a direct line from the discharge electrode.